Open Source Monorail

appengine/monorail/features/prettify.py

+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is govered by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Helper functions for source code syntax highlighting."""
+
+from third_party import ezt
+
+from framework import framework_constants
+
+
+# We only attempt to do client-side syntax highlighting on files that we
+# expect to be source code in languages that we support, and that are
+# reasonably sized.
+MAX_PRETTIFY_LINES = 3000
+
+
+def PrepareSourceLinesForHighlighting(file_contents):
+  """Parse a file into lines for highlighting.
+
+  Args:
+    file_contents: string contents of the source code file.
+
+  Returns:
+    A list of _SourceLine objects, one for each line in the source file.
+  """
+  return [_SourceLine(num + 1, line) for num, line
+          in enumerate(file_contents.splitlines())]
+
+
+class _SourceLine(object):
+  """Convenience class to represent one line of the source code display.
+
+  Attributes:
+      num: The line's location in the source file.
+      line: String source code line to display.
+  """
+
+  def __init__(self, num, line):
+    self.num = num
+    self.line = line
+
+  def __str__(self):
+    return '%d: %s' % (self.num, self.line)
+
+
+def BuildPrettifyData(num_lines, path):
+  """Return page data to help configure google-code-prettify.
+
+  Args:
+    num_lines: int number of lines of source code in the file.
+    path: string path to the file, or just the filename.
+
+  Returns:
+    Dictionary that can be passed to EZT to render a page.
+  """
+  reasonable_size = num_lines < MAX_PRETTIFY_LINES
+
+  filename_lower = path[path.rfind('/') + 1:].lower()
+  ext = filename_lower[filename_lower.rfind('.') + 1:]
+
+  # Note that '' might be a valid entry in these maps.
+  prettify_class = framework_constants.PRETTIFY_CLASS_MAP.get(ext)
+  if prettify_class is None:
+    prettify_class = framework_constants.PRETTIFY_FILENAME_CLASS_MAP.get(
+        filename_lower)
+  supported_lang = prettify_class is not None
+
+  return {
+      'should_prettify': ezt.boolean(supported_lang and reasonable_size),
+      'prettify_class': prettify_class,
+      }